Device for applying active principles for pharmaceutical or cosmetic purposes

ABSTRACT

Device for applying at least one active principle, consisting of a material wherein one or several capsules or microcapsules containing the active principle(s) are distributed in a binder having a sponge-like consistency so that the active principle(s) is/are released when pressure is exerted on the material. The device consists of a first part ( 10 ) and a second part ( 12 ), separated by a tear-off portion ( 14 ), the capsule or most of the capsules or microcapsules being located in the first part close to the tear-off portion, the first part being detached from the second part by tearing the tear-off portion so as to obtain, at the breakage interface, a surface for applying the active principle(s) contained in the first part when pressure is exerted thereon.

TECHNICAL FIELD

This invention relates to devices consisting of a material to carrycapsules or microcapsules containing one or more active principles whichneed to be protected from exposure to air before use, and in particularconcerns a device for applying active principles which is produced froma material of this type commonly used in pharmaceutical and cosmeticapplications.

BACKGROUND ART

In the cosmetic and pharmaceutical fields, many liquid products are soldin bottles. As soon as the bottle is opened for first-time use, contactwith air inevitably entails oxidation which is detrimental to theproduct in the bottle. As a result, it is often impossible to go onusing the product which has lost a part of its properties relativelyquickly.

Other products are sold on some form of substrate, e.g. pads which havebeen pre-impregnated with toilet water or perfume. Once the packaging isbroached, such substrates tend to dry out very quickly as well asproviding a propitious medium for bacterial growth. The samedisadvantages apply to make-up-removal wipes soaked in cleansing milk.

In consequence, using microcapsules was considered. Microcapsuletechnology is well known in the biomedical field. Microcapsules arespherical particles consisting of a solid envelope containing a liquid,solid or semi-solid principle.

Each microcapsule has diameter of between 50 μm and 1.5 mm and thereforeactually constitutes a reservoir. The first industrial application formicrocapsules was in the production of carbonless copy paper since whichtime this technology has been applied to resolve many problems inpharmacy. In practice, because their external covering inhibits exchangewith the outside environment, microcapsules protect medicinal productsfrom diverse chemical and physical phenomena such as humidity, heat andoxidation. Moreover, the rate at which active principles are releasedfrom microcapsules can be controlled and their bioavailability can bethus modulated. This can be achieved by varying a large number ofdifferent technical parameters, including the nature of the materialused to produce the envelope, the relative proportions of the activeprinciples, particle size, and the thickness of the envelope.

The above-mentioned properties have been exploited to produce asubstrate acting as a medium for microcapsules, described for example indocument FR-A-2.754.450. The material used is a foam such as apolyurethane foam, a polyethylene foam or any other polymer with asponge-like consistency. The polyurethane foam, for example, is producedin a conventional process by condensation of a mixture of a polyol andisocyanate in the presence of water which leads to the release of carbondioxide and therefore the formation of multiple cells which give thefinal polymer a sponge-like structure. The microcapsules are added tothe above-mentioned three reagents and everything is thoroughly mixedtogether. When polymerization is complete, the resultant product is asponge-like material with microcapsules distributed in the body of thefoam which acts as a binder.

One of the characteristics of the material of the invention is that thecells communicate with one another so any products contained in themicrocapsules can flow through the material when it is being used. It isimportant to include enough water in the reaction to induce theformation of open cells (i.e. inter-communicating cells). The ideal isof course to have a material in which 100% of the cells are open, butthe above-mentioned applications are possible with a material in whichonly 60% of the cells are open. In practice, in addition to diffusionvia the internal spaces of the cells, the products also diffuse as aresult of impregnation of the material and capillary action. Applicationof a product contained in the microcapsules described in this documentis achieved by exerting pressure on the substrate material in such a wayas to burst the microcapsules to release the active principle(s) thatthey contain, so that these principles can reach the surface of thematerial by diffusion through the open cells.

However, using a substrate material such as is described in documentFR-A-2.754.450 is associated with one major drawback. This is that theapplication surface can become contaminated with unwanted bodies such asdirt, dust or microorganisms, even if the material is sealed inpackaging materials up till use. As a result, the active principles canbecome contaminated when they are released at the surface of thematerial so that topical application can lead to contamination of theskin and pathological consequences.

SUMMARY OF THE INVENTION

This is why the purpose of the invention is to provide a device forapplying active principles contained in capsules or microcapsulesdistributed in a sponge-like material, within which the activeprinciples are maintained perfectly sterile by virtue of the fact thatthe surface of application does not exist until the device is actuallyused.

The object of the invention is therefore a device for applying at leastone active principle, consisting of a material in which one or morecapsules or microcapsules containing the active principle(s) aredistributed in a binder with a sponge-like consistency in such a waythat the active principle(s) are released when pressure is exerted onthe material. The device consists of a first part and a second part,separated by a tear-off portion, the capsule or most of the capsules ormicrocapsules being located in the first part close to the tear-offportion, the first part being detached from the second part by tearingthe tear-off portion so as to obtain, at the breakage interface, asurface for applying the active principle(s) contained in the first partwhen pressure is exerted thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

The purposes, objects and other characteristics of the invention willbecome more apparent in the light of the following description in which:

FIG. 1 shows a preferred embodiment of the device according to theinvention,

FIG. 2 shows a cross section through the device illustrated in FIG. 1,and also an enlarged insert showing the skin formed after formation ofthe sponge-like material, and

FIG. 3 is an enlarged view of the tear-off portion after the deviceillustrated in FIGS. 1 and 2 has been separated into two parts accordingto the principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION

According to a preferred embodiment illustrated in FIG. 1, the deviceconsists of two parts 10 and 12 which can be easily separated by meansof the tear-off portion 14. This portion is formed by a tapering of eachof the two parts 10 and 12 to give a truncated cone-shape with a conicalangle of about 45°, thereby giving rise to a tapered joint 16 where thetwo truncated cones meet. The tapering makes it easier to separate thetwo parts 10 and 12, separation being further facilitated by thebreakage initiation provided by the angular configuration at thetear-off portion. In order to break the device open, one part 12 is heldin one hand and the other part 10 is grasped at the points marked witharrows; a couple then exerted on the first part 10 will induce breakageat the joint 16.

The device according to the invention consists of a sponge-like material(e.g. foam) containing a high proportion of open cells. This foam can begenerated by any means, notably polymerization, e.g. a polyurethanefoam, or any other foam with a sponge-like consistency. Since the deviceis designed to be disposed of after a single use, the material chosenwould preferably be biodegradable.

As shown in FIG. 2, which is a cross section of the device as shown inFIG. 1, the microcapsules 18 are concentrated primarily in the areaaround the tear-off portion, i.e. close to the tapered joint 16. Themicrocapsules may vary in size, e.g. their diameter might be anywherebetween 50 μm and 1.5 mm. However, capsules (rather than microcapsules)with a diameter of several millimeters could be used without departingfrom the scope of the invention.

FIG. 3 shows what the tear-off portion 14 looks like after the two parts10 and 12 have been separated from one another: after breakage along thetapered joint 16, the upper part 10 carries an application surface 20,immediately around which the majority of the capsules or microcapsulesare concentrated. A significant advantage of the invention is that-thissurface is perfectly sterile insofar as it has never been in contactwith any foreign body. The user can then release the active principle(s)from the application surface 20 by exerting pressure on part 10, e.g. bypressing with the thumb and index finger at the points indicated byarrows in FIG. 1.

One characteristic of the invention is that the microcapsules (orcapsules) are as concentrated as possible close to the tear-off portion14. In the case of the material being a form of polyurethane foam, thisis achieved by first injecting the ingredients of the foam into the moldprior to polymerization, then adding the capsules or microcapsules, andfinally the polymerization products again. During polymerization (whichlasts a few seconds), expansion occurs and the microcapsules spread outinto the area which will ultimately be close to the tearoff portion. Insuch a way that the microcapsules are evenly distributed through thefoam, it is possible to vary the foaming time or alternatively togenerate an extremely fluid foam or subject the mold to vibration.

It has been observed that, in certain conditions, the polymerizationprocess in which liquid compounds are converted into a solid foam isassociated with the formation of a skin 22 at the surface of the foam 24as illustrated in FIG. 2. The advantage of this type of skin is not onlythat it protects the device from contamination from outside but it alsoprotects the user's fingers when applying pressure to release the activeprinciple(s).

Application devices or applicators according to the invention can be ofany shape as long as they include a tear-off portion, close to which thecapsules or microcapsules are relatively highly concentrated. Similarly,the device might consist of two different parts, each designed to serveas an applicator for a different active principle. In this case,breakage at the tapered joint 16 would generate application surfaces fortwo applicators after separation. In a special case, the device consistsof two identical parts, both identical to part 10 of the deviceillustrated in FIG. 1, so that separation yields two identicalapplicators. The overall shape can be designed for an esthetic effect,or with ergonomic considerations so that picking up the applicatorautomatically leads to the crushing of the microcapsules in the tear-offportion.

There are many possible applications of the device according to theinvention, mainly in the pharmaceutical and cosmetic fields. Thus, themicrocapsules could contain a skin cleansing product, a liquid soap, adrug designed for topical application, a fragrance, a make-up removalproduct or some other kind of toiletry product.

A particular embodiment consists in sticking together a series ofdevices like that illustrated in FIG. 1 onto a vertical carrier. Thus,whenever the user needs a ready-to-use, sterile applicator, he or shecan just pull one off with one hand until all the devices on the carrierhave been used up.

It is clear that the device according to the invention can be used inany application which requires that the product to be applied not bereleased before the moment of use, release being achieved by thecrushing of capsules or microcapsules. It should be noted that neitherthe number nor the size of the capsules or microcapsules is fixed: thenumber of capsules in the tear-off part could be small, ultimately justa single, large capsule (e.g. with a diameter of 5 mm) close to theapplication surface which is crushed to release the active principle atthe moment when pressure is exerted by the user.

Finally, applications could be considered in which different kinds ofcapsule or microcapsule contain different products which react with oneanother at the moment of release to form one or more active principles.

1. A device for applying at least one active principle, comprising amaterial wherein one or several capsules containing the activeprinciple(s) are distributed in a binder having a sponge-likeconsistency so that the active principle(s) is/are released whenpressure is exerted on the said material, said device comprising a firstpart and a second part, separated by a tearoff portion, the capsule ormost of the capsules being located in said first part close to saidtear-off portion, said first part being detached from said second partby tearing said tear-off portion so as to obtain, at the breakageinterface, a first surface for applying the active principle(s)contained in the first part when pressure is exerted thereon and asecond surface for applying the active principle(s) contained in thesecond part when pressure is exerted thereon, wherein said tear-offportion is formed by two truncated cones which meet at a tapered jointwhere breakage results in separation of said first part from said secondpart.
 2. The device according to claim 1, wherein said tapered jointgenerates, after breakage, said first and second surfaces for applyingthe active principle(s).
 3. The device according to claim 1 wherein saidfirst part and said second part are symmetrical about the tapered joint.4. The device of claim 1, wherein said tear-off portion containsmicrocapsules with a diameter of between 50 μm and 1.5 mm.
 5. The deviceaccording to claim 4, wherein said microcapsules contain differentproducts which react with one another to form active principle(s) whenpressure is exerted on said material.
 6. A method for dispensing afragrance, comprising providing the device of claim 1 wherein afragrance is contained in the capsule(s); tearing the tear-off portionof the device to obtain a breakage interface having two surfaces forapplying the fragrance when a pressure is applied to saidmicroparticles.